Nuclear Spin-Lattice Relaxation in Liquid Crystals by Fluctuations in the Nematic Director

J. W. Doane; C. E. Tarr; M. A. Nickerson

doi:10.1103/PhysRevLett.33.620

Nuclear Spin-Lattice Relaxation in Liquid Crystals by Fluctuations in the Nematic Director

J. W. Doane, C. E. Tarr, and M. A. Nickerson

Phys. Rev. Lett. 33, 620 – Published 9 September 1974

Abstract

We show that a finite cutoff of the hydrodynamic modes (order fluctuations) in the nematic liquid-crystalline phase explains the measured spin-lattice relaxation in this phase. A calculation of $T_{1}$ based upon such a cutoff and a fit to the data of MBBA (4- $n$ -methoxybenzylidene-4′ - $n$ -butylaniline) show this cutoff to be 1 molecular length. At $T_{1 ρ}$ frequencies, far from the cutoff, order fluctuations are shown to be the dominant relaxation mechanism. This is done by comparing the predicted angular dependence of $T_{1 ρ}$ for these modes with that measured in MBBA.

Received 5 June 1974

DOI:https://doi.org/10.1103/PhysRevLett.33.620

Authors & Affiliations

J. W. Doane^*

Department of Physics and Liquid Crystal Institute, Kent State University, Kent, Ohio 44240

C. E. Tarr^† and M. A. Nickerson

Department of Physics, University of Maine, Orono, Maine 04473

^*Research supported in part by the National Science Foundation under Grant No. GH-34164X.
^†Research supported in part by the National Science Foundation under Grant No. GH-34520.